A vehicle air conditioner shown in FIG. 7 includes an air conditioning case 100 for forming an air passage through which conditioned air (i.e., air having temperature-adjusted) flows into air outlets opened to plural positions in a passenger compartment. Specifically, a cooling heat exchanger 110 for cooling air and a heating heat exchanger 120 for heating air are arranged in the air conditioning case 100. Further, the air conditioning case 100 has foot opening portions 130 communicating with foot air outlets from which conditioned air is blown toward the foot area of a passenger in the passenger compartment, a face opening portion 140 communicating with face air outlets from which conditioned air is blown toward the face area of the passenger in the passenger compartment, and a defroster opening portion 150 communicating with defroster air outlets from which conditioned air is blown toward an inner surface of a windshield of the vehicle. Here, the foot opening portions 130 are provided in side walls of the air conditioning case 10 at a downstream air position of an air mixing portion.
A foot door 160 composed of a rotary door is rotatably located in the air conditioning case 100 between the foot opening portion 130 and an inlet port of the defroster opening portion 140 and the face opening portion 150, and a defroster/face door 170 composed of a rotary door is rotatably located in the air conditioning case 100 to open and close the face opening portion 140 and the defroster opening portion 150. The defroster/face door 170 is located downstream of the foot door 160.
The foot door 160 is constructed with an outer peripheral portion 160a formed into a curvature shape, two end plate portions 160b provided at two ends of the outer peripheral portion 160a in an axial direction, and a shaft portion 160c formed at each end plate portion 160b. The end plate portions 160b slide along open surfaces of the foot opening portions 130 of the side walls to open and close the foot opening portion 130. Further, the shaft portion 160c is rotatably located in the air conditioning case 100.
Rotation positions of the doors 16, 17 are changed in accordance with air outlet modes. For example, FIG. 7 shows a bi-level air outlet mode in which both the foot opening portions 130 and the face opening portion 140 are opened by the doors 160, 170, and the defroster opening portion 150 is closed by the door 170. In the bi-level air outlet mode, conditioned cool air is blown toward the face area of the passenger from the face air outlets, and conditioned warm air is blown toward the foot area of the passenger from the foot air outlets.
When the foot door 160 is rotated fully in the arrow “a” direction in FIG. 7, a face air outlet mode is set. During the face air outlet mode, the foot opening portions 130 are fully closed, and only the face opening portion 140 is opened. When the foot door 160 is rotated fully in the arrow “b” direction in FIG. 7, a foot air outlet mode is set. During the foot air outlet mode, the inlet port communicating with the face opening portion 140 and the defroster opening portion 150 is closed, and only the foot opening portions 130 are fully opened. Further, when the defroster/face door 170 is fully rotated in the arrow “c” in FIG. 7 while the foot door 160 is rotated to fully close the foot opening portions 130, a defroster mode where only the defroster opening portion 150 is opened is set. Furthermore, when a defroster/foot air outlet mode is set, the foot door 160 is rotated from the state of the defroster air outlet mode, so that both the defroster opening portion 150 and the foot opening portions 130 are opened.
As described above, in the bi-level air outlet mode and the foot/defroster air outlet mode, the foot door 160 is rotated at a position (a middle position) between the fully closing position of the foot opening portion 130 and the fully opening position of the foot opening portion 130. When the foot door 160 is rotated at a middle position, a clearance is formed between an inner wall of the air conditioning case 100 and the outer peripheral portion 160a of the foot door 160. In this case, cool air or warm air immediately after passing through the heat exchanger 110, 120 before being mixed flows into the clearance. Therefore, the temperature of air to be blown into the face opening portion 140 or the defroster opening portion 150 may be not adjusted to a predetermined temperature.
For example, if cool air from the cooling heat exchanger 110 flows into the clearance when the bi-level air outlet mode is set, cool air having a low temperature may be directly introduced into the face air outlet through the clearance, and comfortable property for the passenger is deteriorated. Further, if a seal member is provided on the inner wall of the air conditioning case 100 to seal the clearance with the outer peripheral portion 160a, a sliding resistance of the foot door 160 is greatly increased, and driving power of an actuator such as a servomotor for driving the foot door 160 is increased.